Forced air heating system



p 0 o.w.o-r1' 2,521,867

FORCED AIR HEATING SYSTEM Filed 001;. 22, 1946 f/v VEN TOR OQAN M 077- Patented Sept. 12, 1950 UNITED CE '1 o I 2 ,521,867 I i ,noncED-f 'RQ-HEATNG SYSTEM I -w ott, SanMarinofiCalifJ Appttafitmottttat2, ieigser l -7 3 l ifcla iriist (012 ;237:533

My invention relates "to a'self contained'heat syste'm e'rnploying asubfloor furnace. More particularly theinventiori relates to a coniiiact forced};air, init ty-pe heating 'sy'stem' in which the ,furnace is adapted to be disposed in arrelatively shallow space below the floor of a building. Li flonyentional: forced airheating-syStems emp1 aleentral-rhea ting plant-with relatively long ducts enclosed by the walls of the building s truc- 'ture. in a frame-type structure ,it-is usually;

necessary to remove cross bracing or a portion -,of the frame-to provide space for; the ducts; thus weakening the, structure;- Inadditiom-there are substantial heat losses from such longductst Anattempt-hastbeen made to simplify such a heating-system by using one or more floor-fur- -naces gproviding-no long ducts, butsupplying heated air through a floor emounted register.-- Such floor: furnaces do not; conventionally-employany means for-:vforcing the air into; the 'roonrgwalbeit itew'ouldabe desirablevto' rorce'the Warm-air: into It'isan object 'ofthe present-*invention to provide: a n'ovel '-heating system i of the forced a ir type employing -a furnace adapted to {be disposed and Warm t air :-strearns:: is undesirian ;the mainiancirculating 7 air into theyrqom and the auxiliary fan supplying astreanr of air a to the yent means- A- further object is to jet a i'n' a relatively shallow space below the floorot a building. This shallow 'space can be the =zone between the g-round floor of a building'and 'the surface ofthe earth or it may be a zone imrndif at'ely -below any 'upperfioor'of ainiilti -s'tory building.

Another objectfis to protide'm-conipact heat mg system of this typeparticularly 'we'll'edapted to "installation in frame=type structuresand whichdoesnot weaken thebuilding' structure; I A further object is to provide a heating system e'rii'ployir'ig a novel relationship. or" su'plplyan d re turn ducts; e. g., a heatingsystem'whichoanlbe iiista lled A near the corner of? a room' below ftlie fioorthrdf'and which will producea desirable circulation of airin the room" to inininiizejfstage nant' zones which are hotter or cooler than'lthe dies'ifedtempefitflre. v I further object is to provide a heating sys tenreinploying a sub floor' furnace which} ante he'apry,maeemetur aanq easilyiinstalled .:?9W 1 f c i d e i zlae rthe airirrom product'sibf' tombt stitnuistharging Tinti') a suitab e vent; It fis 'coriVer'it'ionaI that the tiit e'i'ite'nd upwarmy ma w ubr the building strute tune to a positi'efnabove the root; This weakens the t t ite and-producesa re hazard." It'is an a ject ar the present invr'itiorij to design a heating System-Which needetemploy sueha verticalvent extending 'above' 'the roof. In this connection the" intention includes; amongats' objects the provision of Ta noyel 'draftf-inducing means associated withth'e vent;to;provide acorn trol system which simultaneously controls {the furnace and the draft induciiig means; to proyidea-(ventmipe which mayJextend-in a gen erally horizontal direction through an external Wallof the building;v and to provide ano vel disher 'w i f s t ev t a .o 1 1 :iurtherobjectis td provide a heating .nnit empmymge single electric motor or otherd v e means for operating a main fan and an auxi ary stream of--cool air into-a vent meansearrying products oi combustion to cool theseproducts and aid ninducing a flowthereof; I v irther objects and t advantages of the; inven tion will be evident t -those yskilled the art fromthe following' description and illustration of ;an;; exemplary embodiment,

v- Referring 1' to the: drawinggj w Fig -1 is: a horizontal sectional' view of a building str-ucturep taken just belowtthe-slevel -;of the flgrtz nc r a i e the.in e n-v I \Fig 2 is a vertical sectional. view itaken-t-as indicated by-the'line 21l0f Fig.-1l y o 3 is a. transverse; vertical sectional% view ,takena'as indicated bylthe lines: 3;-3 of;Fig.=. 2.?

= Fig.7. 4 is; a fragmentary-sectional; view ofthe ,vent pipe discharget outlet; taken-pas indicated aby the1ine 4 +4 ofFigd-and o a: :2 gFign 5 -is: a wiring; diagram illustrating :the pref ferred rcontrol circuitz T-he inventiontsisz illustrated as 'aip plied ito building structure of? ther-fra ne type-indicated generally bythe numerall 0. As-best shownin Figs, -2 andt-B the 'usual concrete foundation xl, l", illustrated at one corner; of the buildingtstruc ture or-iroom thereof carries aeplatee l2:

g'Resti-ng- -on this tpl-ate are OiStS"- 3,- -theSer-'j0-ists beingordina-riIy:espaced '16" onoscenters; cfloor 'l 5 rests on the joists andstuds I 6 extend upward- 1y therefromtoform the: walls of ;a-;ropmi| The the studs gbeingfaced;witha suitable interim wall corer ne t The invention includes a sub-floor heating unit or furnace indicated generally by the numeral 2|] and adapted to be secured to the joists l3 in any ber 28 is a plurality of heating elements" 30* spaced from each other to define passages L 9P shown in Fig. 1. Each heating element 30 pro I vides a passage 32 for conducting productsof 11;

combustion upwardly from a burner 33, positioned 7. in a sub-housing 34, to a bonnet 35. The bonnet 5 may be ounded by "a continuation of the side ails ,3 and'iigia d includes a'top wall 35pmv ingthe uses jcollared" lighter ,hole 51' giving eases to the burners: and normally closed" by theusualwindow'ed cover 38 ;One end wall oi thefboni'ietf3'5 provides a'dr'aft *diverter indicated as a plurality of louversts between which air'fmay enter the interior'of the bonnet 3'5; I The. products of combustion are conducted from the bonnet 35 by asuitablevent means which, in accordance with the invention, substantially horizontally disposed? The preferred vent means includeea' vent pip 49 which-"dips below the 'joists' I3 'tof'provide'ahorizontal portion 4| bent o'r-elbowed at42 toexterid beneath the joists and transversely thereof toward one side wall of' the buildingstiucture 101' *The portion 4| may extend horizontallythroughthis side wall. "fl-Iowever, in the pref erred arrangement the horizontal sori 4 I" is' joined by an elbow to avertical section whichcarries another elbow 45 turning -hdi'i aontally ou'twardly through the sidewall of thebuilding'stiucture m;-

- This "then" bow 45 directs the products of fooinb'u's'tion to" a discharge 'outlet fitting 45, best shown in Figs. 1 and 4: "It" includes a box-like structure open at its-"two s'ides anditsbottom to communicate )ivi-ththe surrounding atmosphere thrdiig h f' ntentional-emberscenes-molten 41: frontwall 48' of the discharge"outlet-structure '46 provides mama-rand external' diverters 49 and 50, each preferably in the shape of a pyramid; I 'he inner diverter 49 deflects the products of 'comb'us'tion downwardly and s'idewardly to be discharged through the screen-covered openings.

The-outerdiverter 5q tendsqto deflect any wind blowing in the direction 'of the ar'row5 l to estab lish three beneficial airstreams flowing respectively along the front surface of the front wall 43 toward opposite: sides and toward the bottom thereof; 'Forexample, the lower-surface' of the I pyramidal diverter 5U deflects the wind to create a downwardly moving-stream indicated by the arrow 52 of Fig. 4. This stream aids in 'aspirat ingproductsof combustion from the lower inte- This wall register communicates with a return air duct 51 angling into the shallow space 2! and ending in a circular pipe or return duct connection 58 which opens through one side wall of a housing 60 to communicate with andsupply the return air to an entrance chamber GI. Between the heating chamber 28 and the entrance chamber 61 is a barrier 62 providing a flange surroundiggan ppening 63. In this opening is disposed a ran an connecteditb .ashaftj -EBB' be an electric motor 66, this fan turning in a direction to force :air from the entrance chamber 6! through the heating passages 3| and into an exit chamber 68 wormed by a-h'o'od of the furnace. i v, delivery means for delivering the heated air to on i munieating with the hood 1B is an air the roomo 'lhismeans includes a warm air duct connection at the end of the furnace and communicating with a warm air duct H angling upwardly between the joists I 3 and providing a vertical. portion'l'a disipcse d in one end wall of the room. The warr'n'air duct 1i terminates in a wall register" 13 dischargingtheair through asuitable -"'grille 14 into the room; preferably" at right angles grille 55L; 7 w ,7

Theregister l3- rnay be disposed at any suitable heightin the end wall o'fthefrooin but, for most to the "direction of-flow of the return into the economical installation;"is positioned near the ;flo6r -i-5 as suggested in Fig; 2.- Itwill be noted that the 'angled portions oi'the'returnair duct 51 and the warmjainduct ll clear the foundation H while requiring no substantial cutting of the frame'of the-building. I I

v The flooris cut to provide'an opening '15 aboveime furnace of sufficient size to permit lowerin'g of rthefurnace therethrough. This floor openingis covered by a steel floor plate 16 having asmall opening directly'above the windowed coverr-.38 of the lighterhole-N; this small opening being' cIosedtby. a small vcover-I 1 hingedo'r other- .iwise-secured toth'efloorplate.v 1 The-invention includes a draft-inducing means ionestablishing a forced now of the products of combustionalong, the vent pipe 48 in a direction awayafrom thebonnet;35. The preferred draftinducing means. includesa structure for jetting a stream, of cool aininto the vent pipe in a manner to induce such flow of the products of combustion whilesimultaneouslycocling these products andalsoldrawing, air into the bonnet .35 through the louversfig of the draft diverter. As best at m-memes a d 2,, an-a n efifl en the wont lp t n 4.1.; o the-ve t p pe a t na es in l it re eal 82 ispo ed centrally n t pe A stre m of air fi m t w h. the p pe 8i l twillthus induce'a flow of the products of combusticn along the vent pipe and 'throughthe annular space between this pipe and the air pipe 80. i Ihe pro 52d arrangement for delivering/cool air to 'th air pipe includes an auxiliary 'fan 84 'oi eratively connected to the niotor 165. Prefer ably the'b lll lxilialyjff afi 84 is of 'thecentrifugal or blowertype and'is'mou nted o'n'the exterior oi'the housing fifld Airff rom' the space 2i enters a central opening joifthe auxiliary fan,' as suggested by? the arrow'tfi, v to be pressured and discharged into thejair pipe-en. "The aspirating action of the air; stream reduces thefpres'sure in the bonnet 35 ii'vliereby additional co'ol'air from the space 21 enters the bonnet through the louvers39 to cool the products-of combustioninitially? Further and very's'ubstantial'codling of these products of com bustio-n is -e1fected*by' diseharge'oi the air stream threinto from-the nozzle 82. --The-co'o1ing -of-the 94,10- the-'motor fiii "and "the solrioia' a l s a shows] a wirin'g diagram' for thisgty e' rime 11a- 7 t'ioii. R'eferringIthereto,astp d'dwn trans v ertfi'provides a primary winding connected across (productsoi lcombustionliisso marked thatno en- .peirsive heat-protecting cover is req res t; the N e tr i v a is' preferred that the main. fanfifi ahiti the auxiliary 'fa'ni84 shouldcome into onerationsiniultaneously. "This; is accomplished byyconne'ctingboth'fansdirectly to nemeteresr 'f'It-"islfp're- ,f e'rred also Ithatthese fans be set into opei'ation .simultaneously"with the' burnert3." 5T6 acac apli slithis, afmagnetic valvefflofis' aisposedih the fuel supply pipew the" burner, this 'valveprovid ingausolenoid- 9| adapted,"when"energized to open-the valve; thevalve being; closed when the solenoidis deenergized;

Iffthermostatic control is'dsi'red, a thermostat 93 isdi'sposed at anysuitabie ppsitiop'm th o j and connected, through a suitable Praia conductors 9r" and98"0f a conventional lighting circuit. 'The' low voltage secondary -Windingof this transformer is connectedto arwindingij as for a relay lflfl 'throu'gh the conventional contacts; of

'theg'thrmostatSSl When thethermostaf'call's formore heat,'the WindingQBQ is'energizd'to comv 'plete a circuitthrough contacts IBI 'afl'diflfitb energize simultaneously the motor 66 and the solenoid 9f of'theh'iagnetic valve, 'thu's' startin the"fans"64," errand openin the valve safe; the

I biirh'er.

At this time a circulation orair is" setiipby tiie mainflfan 64 ante a portion Of'this'air'being drawn from the room through the'retinnj'airfduct '51.: "AS this aif-flijWS thrdl lgh the heating chember'za it'is heated by theprcducts of "combustion risingintheipassages '32'fof the heating elements "as? the heated air -being.discharged"through' the 'warm air "duct 1 I -into 'theroom. Thedia ft-im du ing" means" starts to o erate simultaneously with'the-b'urner andrercestheproduetsbf com busti'on along and from'the .vent pipelll'toth fiting '46 to discharge into the atmosphere.

products are spread in 'the' fitting 'fi'as previously described. I g H :7 j f The invention is par-ticularlyrwelt adapted'to economical installationbene ath' the-floor near one corner of the room'toibe'heatecl. 'Wh'en thu's'installed, the direction of flow of return air to the returngrille 1s atrightangles to-thedirection -of=discharge-of-warm air -fromthe-warmair register 13.; This arrangement hasnumerous adv'am tagesas follows: a In the first v place; the"warmair legisterand thereturnregister are disposedcloseto .eachotlrer in one corner of the room' sc -that the return air duct 51 and-the warm-air duct I lean be short and-simple to construct and insta1l.;- in fact, the

return reg-ister can-be-inone- .Wall indirect-alignlee; d sposed in a, relativelyvshallow space-above .a substantiall ment withthe entrancechamber 61 --ancl .-the

-, warm ,air :register can be :inanother (intersecting all-in direct-alignmentwiththe hood -'!ii-.- I be- ;lieve it =to be novel to vemploy short ducts pf this natureextending respectively vto theside end o ffohe furnace. I I g In the second place, this typewof instal-lation provides a very effective circulation-of air in the room tending-tor prevent hot spots or aones of lc'acaliz'ed [temperature inequalityi The (pressured Warm air discharging from-the :warm airregister v 13 fl'ovvs peripherally around theroom before =bemg drawn into the return: air gril1e-55.- 1 Even if f the, warm air and-return;grilles are at the s ame :lev'eL," as suggested in r herel em tim enmityewe r ir to th turn reeist theregistersinayjbe -i 1e a difleren'thelghts o .give}a helixI-lile 'aib na flthe robm, substantially;par llel n t the W 'resultingliflow.tendsto'jfnain uenjmorei'uniioi-mtem eratu inane .Slgl'ithe" rewrite; petitions enhance emigr dnctsjcanbe related to extend; between ex ist ng "studs l 6 ofj'th'ebuilding 'structurei thus elini'ina iinglcomplicated and costiy, sidevviseturns .inthe'ducts'; I

Various changes andmodifications can be-macle without departing rain; 'the -spiritioi the inven tion as defined in the appended claims.

I claimas'rny invention:v

i In a fol-ca air h t h f d bf ft it round surface beloiv-the floor of a robin 5r a-bu t on, the combination-of: arifurnace of asizeto be mounted in said shallow spacegsaidi furnace providing a. heating chamber, internally-passaged heating elements traversing said heating-chambjer, a' burner for delivering; hot products-oncomthe passages of said heating elements and a bonnet adapted to. receive said products 'of 'corhbustion f r orn said 'pa'ssages ofsaid heating elements, said furnace providing, entranceand 'eiz itichainibers at substantially the same elevatio 'nd ositioiied belowsaid bonnet; an-main V fanfo rcing astreamofair through saidfheat- I amber to'beiheate'd bysaid heatingei'emer tsiand thence ihto saidexit chamber; air

delivery means for conducting "the heated air f rom said'exit chamber upwardl'yvabove'said floor to" discharge into said room; a vent pipeextend ing substanti allyv horizontally from said bonnet .i nfsa'id space" below said floor and to Jatrnosviihere utside said building structure at an elevaabove said foundation to. conduct the of"; combustion" from. said bonnet; and ucingn neans including-an auxiliary-fan for pressuring "and. jetting a stream of ico ol air into said vent i pipeein I the general. direction of flow of=said products-bf combustion therein to aspiratesaid-products "of combustionfrom said 2 ,A-heating--system-. as definedvineclaimt 1-, including anelectric-motor and means foam con- ;necting same tooperate both -said .-main -fan and :said auxiliary:ian: sirnu1taneously.

3. A heating -isystemasu-defi-ned in 1 1,; in

I which said: furnace includes .--a housing-providingsaidwntrance chamber, and including aeshort intake means communicating with-said entrance chamber for conducting return air i-rom said room to said :entrance: chamber, said main; fan

forcing -i -saids-return air through-said? heating chamber.

v 4:; A heating,- system asv definedr i Iaim: rain 2- chws ideiurnaceincludes-azhousmeaprovidine iljdingjstructurehaving a foundamiss said entrancechamber, and in which said auxiliary fan of said draft-inducing'means is disposed outside said housing and includes a cool air intake drawing cool air from adjacent said housing, and in which said heating system'ineludes an intake means communicating with'said entrance chamber for'conducting return air from said room to said entrance chamber, said main fan forcing said return air through said heating chamber, and an electric motor for driving both said main fan and said auxiliary fan.

5. A heatin'gsystem as defined in claim 1, in which said draft inducing means comprises a nozzle disposed centrally within the otherwise-unrestricted vent pipe to provide an annular space around said nozzle throug'hwhich said products of combustion may move.

6. In a forced air heating system adapted to be disposed in a relatively shallow space below the floor of a room of a building structure, said floor being supported by spaced joists and said joists being supported by a foundation, the combination of: a furnace having a heating chamber, internally-passaged heating elements extending upwardly through said heating chamber, a burner below said heating elements for delivering hot products of combustion to the lower ends of the passages thereof and a bonnet at the upper end of said furnace to receive the products of combustion from said passages, said furnace being of a size to be mounted in said shallow space and said bonnet being of a size to, extend upwardly between said joists when said furnace is thus mounted; 'means for forcing a stream of air through said heating chamber to be'heated by said heatingelements; air delivery means for delivering the heated air stream to said room above the level of said floor; a vent pipe extending from said bonnetbetween said joists andproviding a portion dipping beneath said joists "and extending substantially horizontally to a position outside said building structure just'above saidfoundation and opening on the atmosphere 'exterior of said buildingadjacent said position;

andme'a'ns for-jettingja flowing stream of air into-saidvent'pi'pe in adirection away'from said bonnet, said last-named means constituting a draft-inducingmeans for establishing a forced flow of saidproducts of combustion along said vent pipe in a directionfrom said bonnet.

7; In a forced airheating system adapted tobe disposed in a relatively shallow space below the floor of aroom of 'a' building structure,said :lioor being s'upport'edby spaced joists, the com-- bination of: a furnace having a' heating chamber, internally-passaged heating elements extending upwardly through said heating chamber, a burner below said heating elements for delivering hot products of combustion to the lower ends of the passages thereof and a bonnet-at the upper end of said furnace to receive the products of combustion from said passages, saidfurnace being of a size to be mounted in said shallow space and said bonnet being of aIsize to extend upwardly between said joists when said furnace is thus mounted; means includinga main substantially horizontally to a position outside said building-structure to communicate with the atmosphere at a' position substantially no higher thansaid bonnet; and draft-inducing means for establishing a forced flow of said products of combustion along said vent pipe in a direction from said bonnet, said draft-inducing means including an auxiliary fanoperatively connected to said main fan and means for jetting the discharge ofsaidjauxiliary fan into said vent pipe to cool said products of combustion therein and force same along said vent pipe in a 'directio away from said bonnet.

8. In a forced air heating system adapted to be disposed in a relatively shallow space below a floor of a room of a building structure, the combination of a furnace of a size to be mounted .in "said shallow space, said furnace providing a heating chamber, internally-passaged heating elements traversing said heating chamber, a burner for delivering hot products of combustion to the passages of said heating elements and a bonnet adapted to receive said products of com bustion from said passages of said heating elements, said bonnet including openings for receiving air from the surrounding atmosphere; means including a main fan for circulating air from said room through said heating chamber and to said room; a vent pipe extending substantially horizontally from' said bonnet in the relatively shallow space below said floor and thence to the exterior of said building structure to conduct the products of combustion from said bonnet; and a draft-inducing means for establishing a forced flow of said products'of combustion alon said vent pipe in a'direction away from said bonnet to induce a flow of air through said openings of said bonnet into the interior of said bonnet to mix with said products of combustion therein.

9. In a forced air heating system adapted to be disposed in a relatively shallow space below the floor of a room of a building structure, the combination of: a furnace of a size to be mounted in said shallow-space, said furnace providing a heating chamber, internally-passaged heating elements traversing said heating chamber, a burner for delivering hot products of combustion to the passages of said heating elements and a bonnet adapted to receive said products of combustion from said passages of said heating elements; means including a main fan for circulating air from saidroom through said heating chamber and to said room; a vent pipe extending substantially horizontally from said bonnet in the relatively shallow space below said floor and thence to the exterior of said building structure to conduct the products of combustion from said bonnetj and a draft-inducing means for establishing a forced flow of said products of combustion along said vent pipe in a direction away from said bonnet, said bonnet includin openings for the entry of air thereinto and said draftinducing means comprising means including an auxiliary fan for jetting a stream of air into said vent pipe in a direction away from said bonnet -to coolthe' products of combustion in the vent pipe and force same therealong in said direction and draw air into said bonnet through said openings thereof.

10. In a forced air heating system adapted to be mounted in a relatively shallow space below the floor of one'corner of a room having'two intersecting walls, said system including: a hot air register in one of said walls; a return register in the other ofsaid walls, said registers being at substantially the same height from said floor and facingatright angles-to each other in said ii 'l '1 sei r sei .fr elm f l rne era e ee mbllfitedil'l said relatively shallow; spacefbeil'eath said one corner of said room,-said-*furnace prm viding an eentrancef ichamberaaniexit.lchamber, a 1

burner for delivering hot; tioni to the ,lower interior; oi i gelen'ientsand a bonnet? f org-combustion from the inppe heating elements; areturn a I g from saidt-return' register own ardly aneln-. wardlyi iinto, said shallow space -to; commun cate with said entrance chamber; a warm air duct extending from said hot air register downwardly diverter for "deflecting theiprgi and inwardly into said shallow space to comdet i rat -ge d; elites and b tom municate with said exit chamber, said Warmair 'lssue from sald a w I and return ducts extending to said heating unit In a hPatmg System adapted to substantially at right angles to each other and be moumed m relatlvely Shallow space below the direction of air flow from said hot air regist floor: of one corner 9 m Pal/mg P ter being substantially perpendicular to the dimtersectmg Walls respepitlvely profldmg hot rection of return air flow to said return register; and return reglsters Sald floor bemg Supported a main fan for forcing air through said return on Spaced ,joists and said 9 5b being Supported air duct and through said entrance heating and by foundatlon 1 respectively below exit chambers and said warm air duct to estab- Walls the m l a furnace of Slze to lish a circulation of air from said hot air regisbe mount-ed relatlvgly shalmispace ter across the axis of said return register and neat? one corner of Said i i peripherally around said room to return to said no 2 51233 35;fig igg g fig figg 2 23 g g' fgggz return register; vent means providing a substantially horizontal portion extending from said bon- 95 2: 253 :35: aggai? f gfig fi i ig fii I h rm 0 e iverin 0 r0 cent the lower end of said one of said walls and mg c amber a U r r g p 35 nets of combustion to the lowerlinterior of the substantially opposite said bonnet, and draft-mpassaged heating elements and a bonnet above ducing means for establishing a forced flow of Said level and sized to extend upwardly into an d products of combustion along said portion interjoist space for receiving products of coma Vent means in 81 5111156151011 away from' bustion from the upper interior of said heating sald bonnet 0 elements; a return duct connection extending In a forced air heating System adap ed to from said entrance chamber toward one of said he mounttd in a relatively Shallow p ce below side Walls; a warm air duct connection extend the floor of one corner of a room having two ing from;- said exit chamber toward the other of int s tin wa ls sp t ly p v din hot a r said side walls, the axes of said connections 'beand return registers, the combination of:,a furing substantially perpendicular to each other; a nace of a size to be mounted in said relatively main fan intaking from said entrance chamber t/sp ce beneath said one corner of S and exhausting into said heating chamber; vent room, said furnace p vi ng an e a ehammeans providing a substantially horizontal .porber, an exit chamb r, heating chamber @011- tion extending from saldbonnet in said intern e a d entrance a d e i chambers. upr h joist space to a position below said floor but i lly-p s d hea in el m n s traversing above. said foundation to communicate with the said heating chamber, a burner for delivering hot atmospl'fre substantially at the level of such po p s f m s n t0 th lower interiervf sition; and draft-inducing means for establishv the passaged heating elements and a bonnet for m a forced flow of. id prod t of combustion receiving products of combustion from the upper along said portion of said vent means ina direcinterior of said heating elements; a return air tion away from i b net,

duct extending from said return register down- In a for ed air heating system d t d to Wardly f inwardly m Said Shallow Space to be mounted in a relatively shallow space below commumcate Wlth Sam entrance chamber; a the floor of a room of a building structure, said warm air duct extending from said hot air regi floor being suppoited by spaced oists and said ister downwardly and inwardly into said shallow joists being Supported by a foundation, said heat Y a ting t one corner of a room having two intersec said hea mg unit substantially at right angles to Walls respectively provldmg hat an and return each other and the direction of air do from i. Said hot register being substantial}; reg1sters, the combmation of: a furnace of a size pendicular to the direction of return air flow to be mounted 2 el tively shallow space, said return register; a main fan for forcing said furnace providing entrance and-exit chamthrough said return air duct and through said bers and a heating h m er connecting said enentrance, heating and exit chambers and said" trance and e t chambers, upright internally-pas Warm air duct to establish a circulation of air sed heating el ment r versing s id hea peripherally around said room; vent means prgchamber, a burner for delivering hot products of riding a substantially horizontal portion extend- Combustion 0 the IQWeI' m t passaged ing from said bonnet in said shallow space I heating elements and a bonnet for receiving said through one of said walls and thence to the products'of combustionfrom the upper interior mosphere, said vent means providing; an utlet 75.of said heating elements, said bonnet being sized sm ie fi om said bonnet, I

- 11 to extend into an interfiisfq spag; e; g heetegl gi pipe extending. from 'saidiutnQc 'ippwal d s iiq hoi;

airQregister; are'turn' air pipe extendip from pipe in .a direction away from said bonnet tc} 15 cool said products of eombustior and aspirate ORAN w. on.

2 l ER E T 2 The following references are of reeor i in tfie file of thiepatent: 1 2' 1 UNITED STA'I'ES PATENTS Y Date Number N'ame 238,135. van Noo 'den Feb. 22,1881 ;fi47 ,3( )1 Hollingsworth Apr. 10, 1900 '1, o'z7,324; v Williams Nov. 4, 1913 1,604,271 Friedm'ani ost,2e,19 "1,767,869 Baumgarten June 24,193!) 2,281,106 MeCpllum Apr. 28, 1942 2,286,115 Shelton .June 9, 942 2,333,602 Van Almeio Nev, 2, 1943 2,376,172 7 Mueller 2 May 15, 1945 

